As you probably already know this year’s hot trend is in wearable gadgets – From the Fitbit tracker which measures your fitness and wellness to the Pebble smart watches, gizmos that are attached to your body are hot news.

But what if you think that even small strap-on devices are a tad too bulky?ed-electrodes/”> Wired is reporting that researchers at the University of Illinois, Dalian University of Technology in China, and the University of California at San Diego have invented a sensor that among other things can measure hydration, activity and temperature and yet can be placed on the skin as a temporary tattoo – like a really thin plaster.

The key thing here is that the tattoo is actually really, really skinny. It apparently has a thickness of 0.8 micrometers at the widest and is designed to be contoured to the skin in a way that makes it simple to measure key body parameters.

John Rogers, who led the study published this week in Advanced Materials said

“Although electronics, over the years, has developed into an extremely sophisticated form of technology, all existing commercial devices in electronics involve silicon wafers as the supporting substrate. Those wafers are mismatched to the body’s mechanics and geometry, he says. The goal here was to develop a system that matches the body more naturally.

“By doing that, you can much more easily integrate electronics, either onto the surface of the skin, or on internal organs like the heart and the brain.”

And this isn’t a breakthrough that is years away. Apparently the researchers behind it aim to have the device available in the next few weeks through a spinoff company, MC10.

Interestingly too the sensor could be used as a human interface, so for example someone could control a video game based on signals from their muscles.